


The undergrounds royal children

by DemonufSans



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), future smut
Language: English
Status: In-Progress
Published: 2017-05-27
Updated: 2017-09-15
Packaged: 2018-11-05 17:10:57
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings, Graphic Depictions Of Violence
Chapters: 3
Words: 3,370
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11017839
Author URL: https://archiveofourown.org/users/DemonufSans/pseuds/DemonufSans
Summary: In a world where survival is everything, four children of the royal family fight to not get hurt, kidnapped or even kill. Chara and Asriel are two protective brothers who will kill anyone who harms their brothers Sans and Papyrus… even if they are monsters.





	1. chapter 1

**Author's Note:**

> hi names demon but you can call me demon~chan this is my baby demonuf!sans' story so please enjoy 
> 
> https://www.youtube.com/watch?v=UbQgXeY_zi4

Survival, kill or be killed. That was the rule of the underground, even for the children of the royal family. Why was this world so cruel to such a precious thing as a child?. Well the answer is simple, they were either killed or protected by their parents, but most are unlucky. 

* * * * * * * * * * *  
He ran and ran, his nonexistent lungs burned like he had been thrown in the fires of Hotland. He had run all the way from Hotland to waterfall trying to get away from the two male monsters chasing him. Why the males were chasing him is because they were trying to kidnap him. They planned to kidnap him and then demand a ransom of the royal family for the skeleton boy. The boy's name is Sans, Sans had gone out to play outside even though he was told to stay inside the castle and not to go out with out one of his older siblings. He was warned but didn't listen to his mom and dad. King Asgore and queen Torial, they rule the underground and are easily angered, only those stupid enough to try and kidnap any of their children were to be dusted.  
Sans kept running as fast as his little legs could go. He was terrified of the males behind him. He regrets not listening to his caretakers and going outside. He doesn't know what to do in this situation. He's so scared that he can't think things through, just run, that’s all he can think of. Everything went black for a moment as one of the males hit him with a bat sending him flying. The red eye lights in his sockets dim a moment. The bat had cracked his skull making marrow bleed out. His marrow bled out more as he hit the ground with a loud thump sound. The other male seemed to be very mad that they had to hit the kid.  
" Don't kill him" male number one said.  
" I'll try " male number two said.  
Pain. Everything in his body hurt. he couldn't move it hurt so much. The males were getting closer to him as he began to pass out.

* * * * * * * * * * *  
The males were going to grab his little brother and he was having none of it. He ran at full speed and attacked one of the males dusting him with his dagger.  
" Jake! … you bra..." He was cut off by a sharp pain.  
The male was knocked to the ground by an extra weight. The male felt pain in his eyes. He screamed as he was stabbed over and over till he was nothing but dust. The boy got up covered in monster blood and dust. He rushed to his unconscious brother on the ground bleeding out marrow.  
" Sans stay with me we're going back and everything will be ok" he whispered as he picked up Sans bride style.  
He began to run back to Hotland carrying Sans in his arm. He feared that with Sans bleeding out his marrow and the crack in his skull. he also felt a dread that Sans would be stuck in a damned bed and not able to move, meaning he wouldn't be able to play.  
The boy who saved sans, well that’s Chara, he's Sans' big brother, at least one of them. Sans' brother Asriel is the elder brother of Chara, Sans, and papyrus (who is a baby bones).  
Chara finally reached the castle that he and his brothers live in along with the King and Queen of the underground.  
" Get Mother and Father!" Chara yelled as he ran into the castle doors.  
The servants and maids run to get the King, Queen, and the healer. Chara waited anxiously as he was breathing hard. Of all things to happen, sans, his little brother was hurt, sans, a crack in his skull. Who knows what that will do to him and the fact that sans was still bleeding out marrow did not help soothe Chara's worry.  
The castle had gotten noisy Asriel had gotten to sans and chara before the king and queen, even the healer. He looked panicked as he ran up to them In a hurry.  
" Chara what happened ?" He asked  
" Assy some bastard monsters tried to kidnap Sans!" Chara yelled in frustration  
" Calm down Chara" Asriel said as calm as he could  
In all honesty, he wanted to punch a wall right now but Chara was in a panic and had his guard on high alert.  
Chara heard them coming, their footsteps were so loud that it gave Chara a headache. The king and queen were running as they were followed by the healer, they looked just as panicked as Chara was as they saw Sans in Chara's arms laying lamp.  
" My Child !" Queen Torial cried  
" What happened?" king Asgore asked  
" Some bastards tried to take Sans and hurt him in the process, I killed them for it" Chara breathed the last part.  
" Let me heal him" the healer signed as he took Sans from Chara.  
W.D Gaster. their healer and Sans' uncle, he was considered as a part of the royal family. Chara looked up to Dr. Gaster. he was learning how to heal with his help. The lessons where long and he was learning to use the magic that Gaster uses. Chara was also being taught how to fight, Undyne and Gaster were in charge of that.  
Gaster finished healing Sans But there was a crack still in his head. He wrapped some gauze and cloth around Sans' head and let out a breath of anger.  
" That crack will not go away it's going to scar" Gaster signed  
Chara wanted to cry his heart out for his brother who he loved so much, LOVE and love where two different things to Chara, LOVE was Level Of ValencE and love a feeling of care stronger than the barrier itself.  
" I'm going to take him to his room when he wakes up get me" Gaster signed.  
" Yes, Doctor" Asriel said as he followed Gaster to Sans' room.  
When they were out sight and the only people it the room was their mom and dad. Chara down in tears, he keeled on the ground and his mom and dad try to comfort him in his moment of panic

* * * * * * *  
Asriel was in sans' room and Doctor Gaster was putting sans in his bed then walked out.  
Asriel just wanted to punch something but he had to stay calm for Chara, plus it'd probably scare everyone if he did that.  
Asriel was never good when it came to controlling his temper. He had to let his temper loose at some points so he asked undyne to help. He know that she was training Chara so that’s why he asked and she had said that he could come to her when he needed to let his anger out  
After an hour sans started wake and Asriel took notice. He rushed to sans' side and called for Gaster. Asriel saw sans open his sockets to reveal his crimson eye lights.  
"Sans oh my god thing goodness!" Asriel cried out  
" Assy?" When Sans spoke his voice sound rushy and dry.  
Gaster had arrived and made sure sans was alright. It sadden Asriel to know that sans would have a scar

Why did these things happen to them? What cruel world!.


	2. chapter two

It had been a week since the event sans was awake but... he would sleep more then normal. Chara had begun his normal training with Undyne and Gaster again and Asriel would stay in the room with Sans, but not today. Sans was in his room alone and bored, but with the pain, he felt, he, in fact, did not want to move a muscle... or was it bone? He felt like harling all over the place.   
Sans lied there in pain. He wanted the pain to go away and never come back, but that just a wish and the cruel reality snuck in like a bitch slap to the face, or like being in the raging storms of anger in Snowdin naked. Sans hated reality in all its glory, he knew that he was weaker than his older brothers but he didn't know that in future he would be forced to be recanted with, he know that Chara was a demon even if no one would tell him and he knew that Asriel could smash a building if angry enough.   
Sans lied there waiting for the pain to subside, he was tired yet just to awake to sleep. He wondered what it'd be like to have immense power more powerful than his brothers.  
Sans slowly drifted to sleep in all the pain he felt  
 * dream *  
At first, it was white like snow but then there was a black and red mist swirling together around him like dirty water and blood. It did not look bad but at the same time it didn't look good, it was getting thicker and the pure white that seemed to drive him mad was fading as the mist came faster toward him. He was confused and frightened by the mist when it touched him, he felt a burning sensation that hurt but felt good and calming. The mist then left him and moved toward a gray book. The book had strange symbols on it, they looked like a magic circle with other symbols inside and strange writing on the sides. The mist seemed to be trying to lure him to the book on the floor in the white space. He hesitated at first but followed shortly after. He picked the book up off the floor and studied it. The mist surrounded him as he sat on the floor. The mist seemed to want to keep the white space out of sight as if it would shock him or make him go mad.   
He tried to open the book but it was locked, he got up from his spot and walked to find the key, looking high and low. He became frustrated that he was not able to find the key to the book. The mist surrounded him again and swallowed him as he tried to beg the mist to give him more time and that he was not ready to wake up.  
*end dream*  
He woke up with a startle. He was covered in sweat and he was about to have an anxiety attack.  
" Sans calm down" he head Asriel"s voice whisper  
" Assy ?" Sans asked when he heard Asriel's voice   
" It's ok Sans, " Asriel said   
Sans calmed down as Asriel stroked his head. He was confused by his dream and curious to know what it meant.  
Sans was in pain again. He groaned in displeasure. Sans growled at the reality that crept in.    
" I'll get Gaster and he'll give you some pain reducer," Asriel said as he pulled out his phone   
" Hello, doctor... yes … could you come and give Sans some pain reducer? … thank you" Asriel said.  
Asriel put the phone back in his pocket and turned to Sans. He walked to Sans' bed and stroked his head. Sans moaned in slight pain but signed when it started to fade a bit. Gaster came into the room and gave sans some pain reducer then he left to do work.  
" Assy ?" Sans whined  as he climbed on to Asriel   
Asriel held onto Sans and stroked his head to smooth him " yes Sans " Asriel's soothing voice hit Sans' ears (?) in a calming way " I'm tired … you won't leave …. r .. right " Sans mumble in a tired voice, Asriel smiled and rubbed circle's  Sans' back. "of course not ...Sans " Asriel whispered.  
* * * * * * * *  
Sans fell asleep in Asriels lap, he looked peaceful in his sleep. Why? why do other monsters like to make their life a living hell. Asriel was still very angry about the instant last week.   
Asriel holds pride in being the bigger brother. He want's to kill the rebels and send each and every one of them to the depths of hell. When Chara brought sans and papyrus home it surprised them all. He was a bit mean, he would ignore sans when he tried to talk to him but after awhile he started to spend more time with him.  
* * * * * * * * *  
*** Back to Sans' Dream***  
He was back in the white space again and the mist was with him again.   
He started to look around again for the key to the book he was holding. As he was walking he saw a skeleton but he did not know or recognize the skeleton. Him cinnamon eye lights looked at the older and then he looked Sans, at first it scared him but he got the carriage to walk up to the other skeleton.  
" Hello," he said, his voice echoed back to him " hi," the other said almost a whisper. " can you .. help me find the key to this book" sans asked holding the skeleton. All the other did, was point to a door in the white space. " in there".  
Sans walked to the door and opened it, it was dark inside. He looked back at the other skeleton than and he nodded. Sans walked into the dark room and the mist followed him in. The door closed behind him making him jump at the sound. It was dark and the only source of light in the room was the lap on the desk. Sans walked to the desk and saw a key, the key he was looking for, it was a black key with a black skeletal dragon wrapped around it. He walked to the desk and grabbed the key.   
As he picked up the key the mist seemed to push him out of the room, he was back in the white space, again. The older skeleton was in front of him now." Open that in 1 year, no sooner and no later" the older said as he kneeled down to Sans' eye level. Sans was going to say something but the older started to turn into mist and Sans felt dazed.  
* * * * end of dream * * * *  
Sans woke up in slite pain. He looked around, the room was dark his dream confused him to bits   
" Sans you up?" Chara asked   
" Chara?" Sans said   
Chara started to pet sans ,Chara smiled as sans fell back to sleep " night sans


	3. chapter 3

**Notes for the Chapter:**

> sorry, i was busy

  
He had been sitting there in bed for three months and now he could leave after the doc said so. He had asked undyne to train him. He knew that Asriel had anger issues and that chara was in fact not human at all and he had gone to undyne because she trained Asriel and chara all the time. Sans had made her promise not to tell anyone, not even the king and queen. For a five-year-old he was street and book smart, for a five-year-old. If sans wanted to he could convince the whole underground he was a girl. Even the King and Queen, he was that smart.   
He lied on his bed a bit bored. He was waiting for the doc to tell him he could get out of that damned bed he was in. It had plagued his mind for what felt years but was only four months, his dream, that dream was on his mind and he couldn’t  for the life of him get it out of his head. Why? , why would a dream seem meaningful, an odd feeling of meaning at that. Sans just sat there thinking. He had asked undyne if she could (when his healed of course) train him, starting with the basics. It had taken him a long time to get her to agree, a long  
His mind came back to thinking about the dream he had. How annoying to have a dream bother you. He lied his head on the Pillows beneath him. Sans tried to think of something other than his dreams.   
Dr. Gaster walked into the room and shut the door making sans jump when it made a loud noise. He walked to the bed and signed "good morning" sans was going to say something back but was stopped when the doc told him to be quiet. It confused him when the doc told him he was to be silent. Dr. Gaster unwrapped the bandages. It hurt but it was worth it to have those heavy bandages off.   
“Sans you will be able to get out of bed but no roughhousing got it” Gaster signed  
“ ok doc” Sans signed to him  
“There is no need to use hands when talking to me, Sans” Gaster signed  
“I know Doc, but it’s more comfortable to talk to you this way” Sans signed back  
“I see” Gaster signed   
“Well your good to go, I’ll just check up on you once a week” Gaster signed  
“ok doc: Sans signed   
Gaster left the room. Sans just sat on the bed thinking of what to do. He was bored. He was not allowed to go outside until he was completely healed up, how boring. Then it came to him, he could go play with pap for a bit.   
Sans got off his bed and headed for the door. Sans open the door and looked around, the hall was a reddish black color with the being covered in candles giving it a haunted house effect. The candles gave a blood orange glow to the reddish black walls making it even creepier than it already was in the hall. The floor in the hall was a dusty red color that would have sent chills down sans’ spine if he were completely sane. The light of the candles made the floor a bit creepy when looked at but this was normal in the underground. Everything was black and red in the underground.  
Sans tiptoed out of his room to head to his little brother's room. His brother papyrus might be happy to see him and that filled Sans with determination. Sans felt as though he should have waited for someone but perhaps he did not care about gut feelings or feelings in general. He walked to the room and opened the door. Peeking around the corner he saw his baby brother in the crib sleeping soundly, he could hear his soft snores coming to his ears making feel at ease. Sans walked into the room and sat by the crib. He felt at peace as lessoned to papyrus sleep peacefully.   
*****  
Asriel saw Sans go into Papyrus’ room. He knew that sans can get lonely and so he goes to ether play with papyrus or watch him sleep. Asriel decided to go into the room and talk to sans because he knew that papyrus was asleep.  
“ Sans?” he whispered   
That Sans’ attention because he turned his head to the door in an anxious manner. When he saw it was just Asriel, he took a dark breath and sighed.  
“ hi Azzy” Sans whispered back to Asriel.   
Asriel walked to where Sans was sitting and sat beside him. Then he picked Sans and sat him on his lap.   
“ how are you feeling ?” Asriel asked in soft tone that stated his concern for the boy in his arms  
“ good, it doesn’t as much anymore and I can walk again,” Sans said tiredly as he became lax in Asriel’s arms   
“ that good, that means you’ll be having dinner in the hall again,” he said as he nuzzled Sans a bit.  
Sans fell asleep in Asriel’s arm after a minute of cuddling and massaging pressure points and joints in Sans’ hands. Asriel sighed when Sans was asleep and gently pop a few finger joints in Sans’s fingers. Asriel had grown to love his two baby brothers. Even though he only knew them for seven months he had grown attached to them like a magnet to metal.   
The sound of whimpering then giggles broke his train of thought. Asriel looked up for Sans and at the crib. Papyrus was reaching off to the ceiling and kicking at nothing, it was silly and cute. Asriel was amused by Papyrus’ actions. Asriel gently lied Sans down and walked to the crib. When Papyrus saw Asriel and he started to coo and blow bubbles. Asriel giggled and was happy that his brothers were with him.

**Author's Note:**

> bye bye see you soon!!! - demon~chan


End file.
